1. Field of the Invention
The present invention relates to a robot controller that deals with input/output signals for a hand, an external jig, or the like, of a robot.
2. Description of Prior Art
An apparatus for programming an operation program for a robot has a plurality of keys for operation, and each of the keys is used to control only one output. When a series of input/output controls (input/output control sequence) is executed while an operation program for the robot is being programmed into the apparatus, a list of input/output control commands stored in the apparatus is displayed in a display device, and a control command is selected from among them. Then, a key for instructing input/output control is pressed to execute the input/output control. That is, in the above-mentioned apparatus, a user has to perform a plurality of operations that include: (A) viewing a displayed list of input/output control commands to be stored; and (B) selecting an input/output control command from among the reviewed list.
Alternatively, if a plurality of keys for instructing input/output controls are provided in the apparatus, a user has to press a plurality of keys, to which outputs are allocated, in a predetermined procedure. Then, a user has to remember the contents of the input/output control allocated to each of the keys, or has to make a note thereof.
The content of the input/output control sequence to be executed is displayed in the display device. However, in order to determine whether the entire sequence has been executed, a user has to remember the sequences, or has to make a note thereof. Further, though the content of a robot operating program that is being programmed into the apparatus is usually displayed in the display device, the display does not indicate whether the displayed information is the input/output sequence to be executed, or whether the displayed information is the content of the programming of the apparatus.
In the introduction of a robot into a production line, it is a goal to shorten the programming time. However, as the number of the input/output control commands for a robot becomes larger, and the system becomes larger, time needed for operation of the input/output control becomes much longer. Further, it takes a long time for recovery from an erroneous operation by a user.
Further, in the above-described robot controller, an input/output control is performed by pressing only one key. Therefore, an erroneous operation by a user is liable to start an unintentional operation. For example, for a robot for moving an article, an erroneous operation by a user is liable to cause the robot to drop and damage an article.